Process of preparing tubes for rear-axle casings



Nov. 19, 1929. A. E. OWEN. T AL Filed June 30, 1928 Patented Nov. 19, 192359 TES ALFRED ERNEST OWEN, 0F SUTTON-COLDFIELD, AND ALBERT COMMON SCOTT, OF

. CODSALIQNEAR WOLVERHAMETON, ENGLAND PROCESS OF PREPARING TUBES FOR REAR-AXLE CASINGS Application filed .Tune 30, 1928, Serial No. 289,521, and in Great Britain March 8, 1328.

This invention relates to the manufacture of rear axle casings and other articles in which it is required to form an annulus with a transverse aXis intermediate the length of a tube. Articles of this character have been produced by forming two oppositely disposed longitudinal slots in the tube where the annulus is to be formed and the tube has then been opened out by suitable internal and external tools to form the annulus with an inwardly extending flange on either side. It has, however, been found that articles produced in this way have been somewhat liable to show a thinning of the metal at those portions of the flanged edges which come adjacent to the rest of the tube at either side of the annulus, owing to a tendency of the metal to be drawn out at such portions during the processes for opening out the centre and forming the inward flanges; and the present invention has for its object to prevent this liability.

According to this invention the metal at the ends of the slots is increased in bulk by subject-ing the tube to endwise pressure and causing the metal at such parts to be mcreased in bulk whereby, when the tube is opened out in the formation of the double flanged annulus, sufficient metal is available at such parts to prevent them becoming thinner than the rest of the metal.

Convenient means for effecting such increase of bulk of the metal of such parts are described with reference to the drawings herewith, of which Figure 1 is a longitudinal sectional view to illustrate means for thickening the metal at the ends of the slots of a tube which is to be formed into a rear axle.

Figure 2 is a part sectional plan view of the means shown in Figure l and showing one of the end pressure tools in operation.

Figure 3 is a vertical sectional view of an alternative form of tools for thickening the metal of the tube in the vicinity ofthe ends of the slots; and,

Figure 4 is a vertical section taken in the plane indicated by the line 4, l, of Figure 3.

Referring first to Figures 1 and 2, A is a length of tube from which a rear axle is to drical hollow on its inner face to it over the external surface of the middle part of the tube. The block D is stationary but the block C 15 mounted in such a manner that it can be pressed up into position under considerable force for instance by hydraulic pressure in any well known manner. E is a transverse bar with rounded side edges. This bar is of a thickness to fit easily into the middle part of each'slot B and the ends of the bar are housed in correspondingly shaped holes in the die blocks. F F are two endwise moving pressure tools with flat'circular end faces adapted to press against the ends of the tube A. Each tool F is adapted to be-moved inwards against the respective end of the tube under considerable pressure for instance by hydraulic pressure in any well known manner.

The tube having been inserted in the die block D with its slots opposite the hole in the die block, the bar E is inserted and the die block C brought up under pressure. One of the tools F (say the left hand tool) is then brought up to exert pressure on the end of the tube which it forces to the right to the positionshown in Figure 2, and such pressure is resisted by the bar E which spreads the metal at the left hand end of each slot B, each slot end is elongated and takes the form shown by broken lines at G in Figure 1 and at the same time the pressure of the bar on the slot-end thickens the metal around the end of the slot. The tube is prevented from bulging outward at these parts by the support afforded by the die blocks.

After this operation the tube ends are reduced in diameter in any well known manner such as by forcingthem endwise through suitable dies, but such process forms no part of the present invention. Afterwards the axle is finished by spreading the centre portion to form the flanged annulus in the manner already well known, and the thickening hollow stationary die having an oval andv larger internal bore shaped to enclose a portion of the larger part of the tube; and as seenin Figure 3 the bore fits against the tube, but as seen in Figure 4 a certain amount of clearance is left. The tool K has a smaller bore J to fit easily over one reduced end of the tube. Between such bores there is formed a taper bore T to fit against the respective taper portion H of the tube. The tube has the usual longitudinal slots B formed in it either before the ends are reduced or subsequently. L is a vertically moving tool pressed down by two vertical membersM of a vertically moving head 0. The toolL comprises apair of lateral projections P P where it engages with the head and a downward block Q, of a width corresponding to the external diameter of the tube and of a thickness corresponding to the width of each slot. The block Q, has a ledge R at each side to bear against the bottom of the respective slot and beneath such ledges at S the width of the block is equal to the internal diameter of'the middle part of the tube. The block is inserted in the tube through the slots with its shoulders resting on the bottom thereof as shown, and then the head is brought down under considerable pressure, such as that of an hydraulic or power press. The efiect is to crush the metal at the ends of the slots and thicken it, the reacting pressure being taken by the taper portion H of the tube bearing upon the taper bore T of the die K. The purpose of the spaces in the die K seenat U in Figure 4. is to allow the tube to bulge in such direction under the action of the block. This, besides relieving the tool, assists in the subsequent process of opening out the slots to form the middle portion of the tube into an annulus, this being performed as before in a manner already well known.

Having fully described our invention, what we claim and desire to secure by Letters Patent is 1. A process for preparing a slotted tube from which is to be formed a rear axle or like article having a middle annular portion with a transverse axis and inwardly extending flanges, consisting in forming in the middle of the tube two longitudinal oppositely disposed slots of a length somewhat less than has heretofore been usual, supporting said middle portion in dies and passing a bar through holes in said dies and through said slots and exerting endwise pressure on each end of said tube, the reaction of said pressure being in each case taken by said bar which by pressing on one end of each slot causes the slot to be elongated and the metal, in the vicinity of the end thereof to be thickened.

2. A process for preparing a slotted tube from which is to be formed a rear axle or like article having a middle annular portion with a. transverse axis andinwardly extending flanges, consisting in forming in the middle of the tube two longitudinal oppositely disposed slots of a'length somewhat less than has heretofore been usual and being reduced in width towards their ends, supporting said middle portion in dies and passing a bar through holes in said dies and through said slots and exerting endwise pressure on each end of said tube, the reaction of said pressure 111 each case belng taken by said bar which by pressing'on one end of each slot elongates and widens it and causes the metal in the vicinity of the end thereof to be thickened.

3. A process for preparing a tube for the formation of a rear axle or the like which consists in providing oppositely disposed slots at the central portion of said tube, sup porting said tube on a bar extending through said slots, applying endwise pressure to the tube to force it in one direction with respect to said bar, releasing the tube from said pressure, and applyingendwisc pressure in the opposite direction to said tube to force the remaining ends of the slots against said bar.

4:. A process for preparing a tube for the formation of a rear axle or the like which consists in a providing oppositely disposed slots at the central portion of said tube, said slots having taperingly reduced ends, supporting said tubeon a bar extending through the central portion of the slots and of substantially the same thickness as the width of the slots, applying pressure to one end of the tube to force it transversely of the bar and bring one end of each slot into pressing engagement with the bearings, releasing the pressure on said tube and applying pressure on the tube in the opposite direction to stretch the remaining ends of said slots and bring their terminal portions in pressing engagement with the bar.

5. A process for preparing a tube for the formation of a rear axle or the like which consists in providing oppositely disposed slots at the central portion of said tube, supporting said tube by a bar extending through said slots and applying pressure between said bar and at one endof each said slot in a manner to lengthen said slot and force up and thicken the metal at the respective end thereof, removing said pressure and then applying it in like manner to the other end of each said slot.

6. A process for preparing a tube for the formation of a rear axle or the like, which consists in providing oppositely disposed taper ended slots at the central portion of-said tube, supporting said tube by a bar extending through said slots and applying pressure between said bar and one end of each said slot in a manner to force out and thicken up the metal at the respective end thereof, removing said pressure and then applying it in like manner to the other end of said slot.

7. The method of preparing a tube for the formation of an axle casing which consists in providing opposite longitudinal slots intermediate the ends of the tube, and thickening the portions of the tube wall about the opposite ends of said slots by displacement of the metal, whereby the slotted portion of the tube may be expanded to form an annulus without decreasing the normal thickness of the metal at said slot ends.

8. The method of preparing a tube for the formation of an axle casing which consists in providing opposite longitudinal slots intermediate the ends of the tube, and applying endwise compression to the portions of the tube wall lying between the outer ends thereof and the adjacent ends of the slots to thicken the tube at said slot ends by displacement of the metal about the opposite ends of the slots, whereby the slotted portion of the tube may be expanded to form an annulus without decreasing the normal thickness of the metal at said slot ends.

9. The method of preparing a tube for the formation of an axle casing which consists in providing opposite longitudinal slots intermediate the ends of the tube, and elongating said slots by endwise compression of the portions of the tube wall lying between the slots and the outer ends of the tube to thicken the tube at said slot ends by displacement of the metal about said slot ends, whereby the slotted portion of the tube may be expanded to form an annulus without decreasing the normal thickness of the metal at said slot ends.

In witness whereof we have hereunto signed our names this 18th day of June, 1928.

A. E. OWEN. A. C. SCOTT. 

